EN 480-11:2005

SLOVENSKI STANDARD
01-december-2005
1DGRPHãþD
SIST EN 480-11:2002
.HPLMVNLGRGDWNL]DEHWRQPDOWRLQLQMHNFLMVNRPDVR±3UHVNXVQHPHWRGH±
GHO8JRWDYOMDQMH]QDþLOQRVWL]UDþQLKSRUYVWUMHQHPEHWRQX
Admixtures for concrete, mortar and grout - Test methods - Part 11: Determination of air
void characteristics in hardened concrete
Zusatzmittel für Beton, Mörtel und Einpressmörtel -Prüfverfahren - Teil 11: Bestimmung
von Luftporenkennwerten in Festbeton
Adjuvants pour bétons, mortiers et coulis - Méthodes d'essai -Partie 11: Détermination
des caractéristiques des vides d'air dans le béton durci
Ta slovenski standard je istoveten z: EN 480-11:2005
ICS:
91.100.10 Cement. Mavec. Apno. Malta Cement. Gypsum. Lime.
Mortar
91.100.30 Beton in betonski izdelki Concrete and concrete
products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 480-11
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2005
ICS 91.100.30 Supersedes EN 480-11:1998
English Version
Admixtures for concrete, mortar and grout - Test methods - Part
11: Determination of air void characteristics in hardened
concrete
Adjuvants pour bétons, mortiers et coulis - Méthodes Zusatzmittel für Beton, Mörtel und Einpressmörtel -
d'essai -Partie 11: Détermination des caractéristiques des Prüfverfahren - Teil 11: Bestimmung von
vides d'air dans le béton durci Luftporenkennwerten in Festbeton
This European Standard was approved by CEN on 28 July 2005.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Central Secretariat or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 480-11:2005: E
worldwide for CEN national Members.

Contents
Page
Foreword .3
1 Scope .4
2 Normative references .4
3 Terms and definitions.4
4 Principle.5
5 Equipment .6
5.1 General .6
5.2 Specimen preparation .6
5.3 Microscopical analysis .6
6 Specimen production and preparation.7
6.1 Specimen production .7
6.2 Preparation of test surface.7
7 Microscopic procedure.8
7.1 Basic procedure.8
7.2 Values recorded .9
8 Calculations.10
8.1 Data obtained .10
8.2 Total traverse length.10
8.3 Total air content .10
8.4 Total number of chords measured .10
8.5 Specific surface of the air.11
8.6 Paste: air ratio .11
8.7 Spacing factor .11
8.8 Micro-air content.11

8.9 Air void distribution.11
9 Test report .13

Annex A (informative) Theoretical basis of calculation involved in Table 1 .15
Annex B (informative) Worked example of the calculation of air void distribution.18

Foreword
This European Standard (EN 480-11:2005) has been prepared by Technical Committee CEN/TC 104
“Concrete and related products”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by March 2006, and conflicting national standards shall be withdrawn at
the latest by March 2006.
This document is part of the series EN 480 "Admixtures for concrete, mortar and grout – Test methods" which
comprises the following
Part 1 Reference concrete and reference mortar for testing
Part 2 Determination of setting time
Part 4 Determination of bleeding of concrete
Part 5 Determination of capillary absorption
Part 6 Infrared analysis
Part 8 Determination of the conventional dry material content
Part 10 Determination of water soluble chloride content
Part 11 Determination of air void characteristics in hardened concrete
Part 12 Determination of the alkali content of admixtures
Part 13 Reference masonry mortar for testing mortar admixtures
Part 14 Admixtures for concrete, mortar and grout - Test methods - Part 14: Measurement of corrosion
1)
susceptibility of reinforcing steel in concrete - Potentiostatic electro-chemical test method
This document is applicable together with the other standards of the EN 480 series.
This document supersedes EN 480-11:1998.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland
and United Kingdom.
1) This part is under preparation
1 Scope
This document describes a test method for determination of the air-void structure in a hardened concrete sample
which contains entrained air. The air-void structure is described by means of the following parameters, which are
defined in Clause 3.
i) Total air content
ii) Specific surface of air void system
iii) Spacing factor
iv) Air-void size distribution
v) Micro air content
The method as described is only suitable for use on hardened concrete specimens where the original mix
proportions of the concrete are accurately known and the specimen is representative of these mix proportions.
This will generally be the case only where the concrete concerned is produced in a laboratory.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 480-1, Admixtures for concrete, mortar and grout – Test methods – Part 1: Reference concrete and
reference mortar for testing;
EN 934-2, Admixtures for concrete, mortar and grout – Part 2: Concrete admixtures –Definitions, requirements,
conformity, marking and labelling
ISO 1920-3, Testing of concrete - Part 3: Making and curing test specimens
3 Terms and definitions
For the purposes of this European Standard, the following terms and definitions apply.
3.1
air void
space enclosed by the cement paste that was filled with air or other gas prior to the setting of the paste. This
does not refer to voids of submicroscopic dimensions, such as the porosity inherent in a hydrated cement
paste. For the purposes of this test method, all voids within the cement paste are considered that are visible at
the test magnification with an intercepted chord length of up to 4 mm, other than obvious cracks
3.2
total air content A
proportion of the total volume of the concrete that is air voids; expressed as a percentage by volume
3.3
paste content P
proportion of the total volume of the concrete that is hardened cement paste, expressed as a percentage by
volume. This is the sum of the proportional volumes of cement, mixing water and any admixtures present. For
the purposes of this test method it is calculated from the batch weights of the test concrete.
3.4
specific surface of air void system α
-
calculated parameter representing the total surface area of the air voids divided by their volume; units are mm
. The calculation method used is based on the average chord length and is valid for any system of spherical
voids
3.5
spacing factor
calculated parameter related to the maximum distance of any point in the cement paste from the periphery of
an air void, measured through the cement paste; units are mm. The calculation of this parameter assumes
that all air voids present are of uniform size and are evenly distributed through the cement paste such that the
model system has the same total volume and surface area as the real system
NOTE This model is an approximation; the value obtained is probably larger than the actual value.
3.6
air-void distribution
set of calculated values of the number and/or volume of air voids of various diameters within the hardened
cement paste
NOTE The model used for this calculation assumes that only voids having diameters of certain discrete values are
present. This model will therefore lie between the real case and the single diameter model that is used in the calculation of
the spacing factor. A graphical representation of the distribution can be obtained by plotting the volume of air attributable
to each size of void, either as a volume percentage of the cement paste or as a proportion of the total air content.
3.7
micro air content A
calculated parameter representing the air content attributed to air voids of 0,3 mm (300 µm) diameter or less.
The value for this parameter is obtained during the calculation of the air void distribution
3.8
traverse line
One of a series of lines across the polished specimen face traced by the relative motion of the microscope and
specimen during the test
3.9
length of traverse T
tot
total distance traversed across the surface of the specimens during the test measurement. It is made up of two
parts, the total traverse across the surface on solid phases, T , and across air voids, T , in each case the units
s a
are mm
3.10
chord length l
distance along the traverse line across an air void, units are µm
3.11
chord length classification
chord lengths across individual air voids are classified into classes based on the length of the chord. The total
number of chords in any particular class, i, is designated by C. in8.9 and Table 1 contain details of the boundary
i
values for the classes
4 Principle
Hardened samples of air-entrained concrete are sectioned perpendicular to the original free upper surface to
produce specimens for analysis. These specimens are then ground and polished to produce a smooth flat
surface finish suitable for microscopic investigation.
The air void structure is examined by scanning along a series of traverse lines running parallel to the original free
upper surface. The number of air voids intersected by the traverse lines are recorded, as are the individual chord
lengths of the traverse across the air voids.
A mathematical analysis of the recorded data then allows a description of the air void system in terms of the
required parameters.
Other methods of air void analysis such as the point count method may be used provided that they can be
shown to give essentially the same results for the air void parameters required as the method described herein.
In the case of dispute the method described in this document shall be used.
5 Equipment
5.1 General
The following list of equipment has been found suitable for this test. Other apparatus may be used if it can be
shown to produce satisfactory results. Not all the equipment may be required for individual test measurements.
5.2 Specimen preparation
a) Diamond saw;
b) Grinding machine. One or more instruments able to provide a finished surface of the required quality.
These include instruments with a cast iron disc, usually with a minimum diameter of 400 mm, used in
conjunction with silicon carbide powder of various grain sizes (typically 120, 60, 30, 16 and 12 µm) or
instruments with special grinding discs of the varying grain sizes;
c) Refrigerator and oven;
d) Various chemicals for treatment of the polished surface, including; glycerol, stamp ink (matt or dull black,
not water soluble), zinc paste and gypsum powder (grain size ≤ 3 µm).
5.3 Microscopical analysis
a) A motorised or hand operated cross traverse table. This consists of a platform, on which the specimen
rests, which is mounted on lead screws by means of which it can be moved smoothly in two
perpendicular directions. One lead screw is required for movement in a direction perpendicular to and two
lead screws for movement parallel to the original upper surface. The lead screws should be capable of
providing a measure of the total distance travelled to an accuracy of 1 %;
b) Lighting equipment;
c) A means of recording the traverse distances and the total number of air voids traversed, divided into
classes based on the individual chord lengths;
d) Stereoscopic microscope, magnification (100 ±10) x. The instrument used must be capable of providing
the necessary resolution to classify the chords measured into classes as detailed in section 7.2. Other
forms of imaging may be used, such as a television camera mounted on the microscope with linked
monitor. In these cases the image used for measurements shall be selected so as to produce results for
voids counted which are consistent with those produced using direct visual examination through a
microscope.
NOTE Use of imaging systems of other magnification may lead to differences in the diameter of the smallest visible
voids. These may lead to counting variations and different values for calculated parameters.
6 Specimen production and preparation
6.1 Specimen production
Two samples, of minimum dimension 150 mm, shall be cast from the concrete under investigation. For testing
admixtures in accordance with EN 934-2 the concrete shall conform with EN 480-1. Suitable sample
geometries include 150 mm cubes or 150 mm diameter cylinders. Manufacture and curing of the samples
shall conform with ISO 1920-3.
After the concrete has been cured for a minimum of 7 days, a specimen approximately 100 mm wide by
150 mm high by 20 mm thick shall be cut from the approximate centre of each sample, such that the four cut
surfaces are perpendicular to the sample face that was uppermost during manufacture, see Figure 1. One of
the largest faces of each specimen is used, after preparation, for microscopic examination.

Key
1 Upper face during manufacture (original free upper surface)
Figure 1 — Production of 150 mm x 100 m x 40 mm specimen from 150 mm sample
(approximate dimensions)
6.2 Preparation of test surface
The intended test surfaces, one for each specimen, shall be wet ground until they are flat.
After wet grinding, a finely lapped finish to the test surface shall be produced. When this is complete the test
surface shall be cleaned to remove any residues.
NOTE The time required for wet grinding depends on the equipment used and will take approximately 5 min.
During this procedure, care should be taken to ensure that the test surface and the opposite face of the
specimen are as plane parallel as possible.
The exact procedure used will depend on the equipment available. The purpose of the lapping procedure is to
produce a surface suitable for microscopic examination of the air void structure within the concrete. A suitable
surface should have a matt sheen when dry and have no noticeable relief between the paste and aggregate
surface. The edges of voids should be sharp, and should not be broken or rounded. Care should be taken at
all stages of the grinding and lapping processes to ensure that voids do not become clogged with grinding
residues.
After the fine lapping is complete, the test surfaces should be cleaned to remove any residues. Suitable
methods are to use water and compressed air or a suitable fine brush. Care should be taken during the
cleaning process to ensure that the edges of the voids are not damaged. This may be of particular importance
if ultrasonic cleansing is used.
Reproducible results can be expected only with careful and appropriate fine lapping and cleaning of the test
surfaces.
The specimen surface can be treated to produce a better contrast between the air-voids and the cement paste,
should this be required by the intended measurement procedure. It is likely that this will be necessary if
automatic procedures are to be used. This can be done by first applying ink to the surface of the specimen
from a stamp pad or roller. Care should be taken to prevent the ink from sinking into the air-voids. The
specimen is then placed in an oven at 50 °C for 4 h. It is then covered with zinc paste and refrigerated before
any excess zinc paste is removed. Finally, the surface is covered with fine gypsum powder which is pressed
into the zinc paste filled air-voids. The excess gypsum powder is then removed with a scraper.
7 Microscopic procedure
7.1 Basic procedure
The specimens are placed on the cross-traverse table so that the traverse lines which are to be followed run
parallel to the original free upper surface of the specimen.
A minimum traverse distance of 1200 mm is required for each specimen, giving a minimum total of 2400 mm
per test. A number of traverses across the specimen face are made to give the required total distance. As it is
often difficult to ensure a perfect surface finish to the very edge of a specimen, care shall be taken to ensure
that any damaged area is not included in the traverse length. The traverse lines shall be laid out as follows,
see also Figure 2.
a) Four traverse lines are made in the upper region of the surface, across its width. The uppermost line
should be approximately 6 mm from the upper edge of the specimen and subsequent lines should be
spaced by approximately 6 mm from each other;
b) A further four traverse lines are made in the lower region of the surface. The lowest line should be
approximately 6 mm from the lower edge of the specimen and subsequent lines should be spaced by
approximately 6 mm from each other;
c) Further traverse lines are laid out in the central region of the surface, spaced by approximately 6 mm from
each other, so as to produce the total traverse distance required. A minimum of four traverse lines will be
required in this area, more may be needed to provide the required minimum traverse lengths if damaged
areas exist on the surface.
SIST E
...